Frequently, in the development of commercial or military products, it is desired to test the product's tolerance to sine vibration of selected frequency and amplitude or to random vibration with multi-frequency content. Conventional apparatus for performing this vibration testing include a vibration generator for generating vibration and a sliptable coupled to the vibration generator for supporting the object to be tested. Known vibration testing apparatus also typically include clamp fixtures for securing the test object to the sliptable or directly to the vibration generator.
In the past, to test an object's tolerance to vibration along more than one axis, the object was unclamped from the sliptable, repositioned, and clamped again to the sliptable or to the vibration generator in a new angular orientation therewith. This unclamping and repositioning was repeated for each axis of the object along which vibration testing was to be performed.
To minimize the time and effort required to reposition an object when multi-axis testing of the object is to be performed, a three-axis vibration test fixture of the type disclosed in British Patent Application No. 8522501, filed Sept. 11, 1985, was developed. This test fixture includes a cube to which a test object(s) is(are) secured and a clamp assembly for securing the cube to a vibrating table or head expander. A shaft is attached to one corner of the cube so as to diagonally extend along an axis that intersects the center and opposite corners of the cube. When it is desired to reposition the test object for vibration testing along a different axis of the object, the clamping assembly is actuated to release the cube. Then, the cube is repositioned by manipulating the shaft either manually or mechanically using an electric motor until the cube is in the desired new position. Thereafter, the cube is reclamped to the vibrating table.
While the invention of British Patent Application No. 8522501 reduces somewhat the amount of time required to test an object, especially an awkwardly-shaped object, significant time and human involvement is still required to reposition the object for testing along more than one axis of the object.